The search for new antibiotics produced by soil microorganisms has encompassed the screening of various genera of bacteria, and fungi including many species within each genus and many strains within each species.
Among the microorganisms that have received somewhat less attention than others are those that belong to the genus Nocardia. This genus has the narrow hyphae of the Actinomycetales and is characterized by fragmentary substrate mycelium. The generic identity may be further supported by a cell wall of type IV as described by H. A. Lechevalier and M. P. Lechevalier, A Critical Evaluation of the Genera of Aerobic Actinomycetes, pages 393-405, in The Actinomycetales (1970), edited by H. Prauser and published by Fischer, Jena. This genus is further characterized by a whole-cell sugar pattern of type A as described by M. P. Lechevalier, Identification of Aerobic Actinomycetes of Clinical Importance, J. Lab. Clin. Med., 71(6), 934-944 (1968).